Today in History—July 20: First Contact with a Hazardous Surface
On this day in 1969, the Apollo 11 mission put men on the Moon. As Neil Armstrong’s boots made contact with the lunar surface, his words became etched in history: “That’s one small step for [a] man, one giant leap for mankind.”
And Armstrong’s second sentence? Not as grand. “And the—the surface is fine and powdery,” the radio transcript reports. “I can—I can pick it up loosely with my toe,” he added, which sounds like any one of us checking out a pleasant beach.
But these remarks about the powdery surface followed years of concern that dust on the Moon might be hazardous. Some believed that billions of years of meteorite impacts had accumulated a layer of dust miles deep. A probe—or a person—attempting to land might be swallowed whole. Fortunately, NASA’s Surveyor probes had demonstrated that the surface was solid enough to support a spacecraft.
However, we were right, in a sense: Lunar dust is far from harmless. Armstrong’s remarks turned out to be our first account of a hazard that would plague all future lunar expeditions.
Lunar dust is sharp. All 12 men who had walked on the Moon during the Apollo missions experienced short-term respiratory problems from inhaling it. It wore down vacuum seals and the astronauts’ boots, and it scratched Apollo 17 astronaut Harrison Schmitt’s sun shade so badly that it impeded his vision. The Moon may not be coated by miles-deep quicksand, but it is covered with countless microscopic knives.
Upon returning to Earth, the crew of Apollo 11 had to fill in a customs form at Honolulu Airport to declare their cargo of Moon rocks and samples.
And these knives stick: Lunar dust carries an electric charge, causing it to adhere to things like astronauts and spacecraft. This charge even makes the dust levitate, endangering things above the ground.
The Artemis program plans to return humans to the Moon in 2028, and NASA scientists are working to defeat lunar dust. Space suits that could electrically repel the dangerous particles are in the works, and at the Johnson Space Center, experiments are run with simulated lunar dust made from volcanic rock to test interventions.
We can only guess what the Artemis crew’s first words on the lunar surface might be. But don’t be surprised if discussions of dust dominate the radio transmissions that follow.
- ~4 days: Time to travel to the Moon
- 150 bpm: Armstrong’s heart rate during the Moon landing
- ~22 hours: Time spent on the lunar surface by the Apollo 11 astronauts
- 1917: The Corfu Declaration is issued, calling for a unified Yugoslav state
- 1968: The first Special Olympics is held in Chicago
- 2021: American aviation pioneer Wally Funk becomes the oldest person to go to space
